Jack is in charge of the case of a three month old corpse found in the coal bin of an abandoned farm house. The body is eventually identified as that of a well known thief, but Jack has little to go on. DS Liz Maud has a case of a child abuser who is injecting children with water. Jack recalls a similar case and when they learn he is now in the area, have an immediate suspect. Jack feels sorry for him however and concludes that he can't be the person they're after. However, when two children are killed, both with indications of having injections, Jack may be in the soup. Supt. Mullett advises him that he will have no choice but to advise the Chief Constable and that it will likely lead to a disciplinary hearing. Fortunately for Jack, he sees a number of holes in Maud's case leading him to the the real killer.